Oil bath air filter



y 14, 1946- A. M. GOODLOE OIL BATH AIR FILTER Filed Nov. 2, 1944 Al G Z' red 00a" 00 i;

Jttar/z aya tor casing l0, having at its lower Patented May 14, 1946 PATENT OFFICE 2,400,347 OIL BATH AIR FILTER Alfred M. Goodloe, Montclair, N.

Metal Textile Corporation, West 1., assignor to Orange, N. J.,

a corporation of Delaware Application November 2, 1944, Serial No. 561,545

6 Claims.

This invention relates to improvements in air filters or cleaners, and the invention has reference, more particularly, to an improved air filter or cleaner of the oil bath type, such e. g. as used for pur ing dust from air to be delivered to and through a carburetor or charge forming device serving an internal combustion engine. w This invention has for an object to provide a novel construction of oil bath air filter adapted to develop high initial velocity of air movement in contact with 'the oil content of the filter, whereby not only to efliciently carry oil to the filter medium for bathing and coating the latter therewith, but also to develop high initial air velocity within the receiving section of the filter medium so as toincrease dust impingement efficiency and obtain fluid mixture of dust and oil without tendency of the mixture to thicken or cake; saidfilter medium being so formed and arranged as to permit air flow therethrough with diminishing velocity, whereby risk of oil escape or pull-over at the point or air discharge therefrom is avoided, and gravitation of oil and its accumulated dust content through the filter medium for discharge therefrom is facilitated.

Another object of this invention is to provide. in an air filter having an oil bathed filter medium, novel means to facilitate the withdrawal and discharge of dust laden oil from the medium.

Other objects oi. this invention, not at this time more particularly enumerated, will be understood from the following detailed description oi the same.

An illustrative embodiment shown in the accom Fig. 1 is a vertical cross sectional view oi. an

of this invention is oil bath filter apparatus according to this invention; and Fig. 2 is in p rt atop elevational and part horizontal sectional view of the same, taken on line 22 in Fig. l.

Similar characters or reference are employed in the above described views, to indicate corresponding parts. I v

Referring-to the drawing, the novel air filter apparatus comprises an upwardly open housing end a basin'section H of reduced diameter irom the central bottom portion oi which depends a sump section l2 further reduced diameter. The side wall of said'housing or casing I0 is joined to the side wall of the basin section l l by an'inwardly bowed annular wall section l3 of convex cross-sectional shape.

Extending downwardly through the upwardIy open top of the housing or casing l0 into the indrawing, in which: 38

terior thereof is an container I! which upwardly open filter medium is of a diametersmaller than that of said housing or casing, whereby an upwardly and outwardly open space is formed 5 therebetween, said space providing a, descending airintake passage l5- leading to the basin section II of the housing or casing in. Said container l4 i provided with a bottom wall is which inclines downwardly and outwardly from a a central opening I1, with which it is provided, to join the container Side wall. Said bottom wall and container side wall are joined by an out- ,wardly bowed annular wall section l8 of convex cross-sectional shape, which,-when the container I4 is assembled within the housing or casing to, and above the basin section H of the latter, is opposed in spaced relation to the annular wall section purposes hereinafter to be referred to. Connected with the margin of the upwardly open end of said filter medium container II is an out- '-"wardly projecting annular flange l9.

' The filter medium container ll is supported within and in operative relation to'the housing or casing in by means or a plurality of circumferentially spaced bracket elements 20 which are afllxed to the walls of said housing or casing in inwardly oilset upstanding position, so as to proiect upwardly from and beyond the open top of 80 said housing or casing. Each bracket element 2013 provided with an axially projecting screws a supporting shoulder 22 therebetween.

The open top of the filter medium container "is closed by a cover plate 23 which inclines downwardly and inwardly from its outer marginal portion to merge with a central portion 24 which is aligned with and spaced above the central'opening ll of the container bottom wall I6, 40 thus providing a laterally open axial air-delivery passage 25 withinthe container M which is closed at its upper en by said central portionil of the'cover plate 23. Connected with the mar in of said cover plate 23 is an outwardly projecting 65 annular flange 26, which overlies the flange IQ of said container ll. -When the cover plate 23 is applied to the container I4, an annular filter medium enclosing, chamber is formed which is bounded bytop and bottom walls which converge upon said axial air delivery passage 25, whereby said chamber widens outwardly from said delivery passage, so as to progressively enlarge toward its outer boundaries. Said cover plate 23 is provided with clean air discharge 56 ports or openings 21 which are disposed around i3 01 the housing or casing, for

threaded stud 2| of reduced diameter to provide and in communication. with the enlarged outer portions of the container chamber.

The, reference character 28 indicates the top cover or 'dome of the air filter apparatus, the same being disposed to overlie the filter medium container cover plate whereby to provide therebetween a clean air collection chamber 29. Connected with the margin of said top cover or dome 28 is an outwardly projecting annular flange 30 which overlies the cover plate flange 26. Said top cover or dome 28 is provided with an air outlet neck 3|, to which may be suitably coupled a clean air conduit 32, through which the clean air discharge from the apparatus may be led to a desired place of use.

The flanges I9, 26 and 30 of the respective filter medium container 14, cover plate 23 and top screw onto the projecting ends oi said studs 2i.

The chamber of the container I4 contains an be subsequently The basin The opposed convex wall sections l3 and I8, respectively of the housing or casing ill and container l4, by their spaced opposition and shape provide a Venturi-like passage 39 between the air intake passage I5 and the upper interior of the basin section which underlies the filter medium container l4. Formed in the convex wall section l8 whereby to afford communication between the outer lower portion of the chamber of the filter medium container l4 and the restricted part -of .said Venturi-like passage 39 are openings i0 through which dust laden oil may be withdrawn from said filter medium container.

When the air filter apparatus of this invention is operatively connected with the carburetor or other charge forming device of an internal combustion engine, air will be drawn by the suction strokes of the engine pistons into the apparatus through the air intake passage I 5, t be thence directed across the surface of the oil 3'! contained in the basin section II. The oil segregated by the metering plate 38 from the main body of oil constitutes but a relatively small part of the whole by contact of the ingoing moving air stream therewith. As the air sweeps over the oil th'us exposed to contact therewith, the

agitation of the oil thereby is sufficient to spraycontainer chamber, through the portions 35 of the filter medium which jacent to said escape ity of the air, as it progresses through the filter medium, tends. to dim thus permitting the oil and dust mixture washed along therethrough by the air to become increasingly subject and responsive to the force of gravity, so that said mixture tends to descend through the filter medium v a of its bottom and side walls conof ingoing air above and diat the that. tiguous to the path rected toward the oil holding section, and means and collect in the outlying bottom portion ofthe container chamber. upwardly and outwardly from the outlying portions of the filter medium at reduced velocity through the discharge ports or openings 21 of the container cover plate 23, the movement of they discharged air is in counterfiow to gravitation of the oil and dust mixture and therefore efllcient separation of the oil and dust from the air is further assured, and undesirable oil pull-over (i. e. discharge of oil particles with the outgoing air) is avoided. I

The separated oil and dust mixture will discharge from the bottom interior of the filter medium container ll through the escape openings 40. Since these escape openings Ill communicate with the restricted portion of the Venturi-like passage 39 through which the ingoing air must pass on its way to the filter medium of the apparatus, the increased velocity of the air stream moving through said Venturi-llke passage tends to reduce pressure in the area of the air path adopenings 40, thus inducing a suction effect upon the oil and dust mixture within the lower bottom portion of the container ll which substantially increases the rate of overfiow of the mixture through the escape openings 40, and thus-better purge the filter medium of collected dust so that the period of useful life of the filter medium is substantially prolonged, before necessity for removal, cleaning and replacement of the filter body is required. The oil and dust mixture thus withdrawn medium and its container is driven down by the ingoing air stream upon the body of oil contained in the lower portion of the apparatus, so as to be caught thereby, and by sinking down there through is caused to settle and collect in the sump section l2 of the housing or casing It.

It willbe understood that some changes may be made in the embodiment of this invention Since the air is discharged from the filter said container without departing from-the scope thereof as defined in the following claims. It is therefore intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not on a limiting sense.

I claim:

1. An air filter apparatus comprising an upwardly open casing having an oil holding section,

at its bottom, a filter medium container supported witin said casing 'adjacently above the oil ing section, said container having its side walls inwardly spaced from the casing side walls to provide an annular ingoing air passage communicating with the oil holding section, said container holdto collect and direct clean air emitted through the container air discharge means for delivery to a place of use. I

2. An air filter apparatus comprising an upwardly open casing having an oil holding section at its bottom, a filter medium container supported within said casing adiacentlyabove the oil holding section, said container having its side walls inwardly spaced from the casing side walls to provide an annular ingoing air passage communicating with the oil holdin'g section, said container having central air intake means leading through its-bottom wall and air discharge means 'in its top wall adjacent the side walls, bottom and top walls ofsaid container being formed to provide an annular container chamber progressively and symmetrically enlarging in vertical cross sectional area from its central air intake means toward the container side walls and beneath said air discharge means, an annular interstitial mass of filtering material filling said annular container chamber around and in communication with said air intake means thereof, said filtering material being arrangedand graded toprogressively decrease gradually from a maximum density adiacent the container air intake means to a minimum density adjacent the container side walls and beneath the container air discharge means,

said container having oil and dust mixture disgoing air above and directed toward the oil holding section, and means to collect and direct clean -air emitted through the container air discharge means for delivery to a place of use.

3. An air filter apparatus comprises an upwardly open casing having at its bottom an oil basin section of reduced diameter, a filter medium container supported within said casing adjacently above the oil basin section, said container having its side walls inwardly spaced from the casing side walls to provide an annular ingoing air passage communicating with said oil basin section, having central air intake means bottom wall and air distop wall adjacent the side leading through its charge means in its walls, bottom and top walls of said container be-' ing formed to provide an annular container cham. ber progressively and symmetrically enlarging in vertical cross-sectional area from its central-air intake means toward the container side walls and beneath said air discharge means, an annular interstitial mass of filtering material filling said annular container chamber around and in communication with said air intake means thereof, an inwardly directed convex wall section at the juncture of the casing and oil basin section side walls, an outwardly directed convex wall section at the juncture of the container bottom and side having central air intake means leading through its bottom wall and air discharge means in its top wall adjacent the side walls, bottom and top walls of said container being formed to provide an annular container chamber progressively and symmetrically enlarging in vertical cross'sectional area from its central air intake means toward thecontainer side walls and beneath said air discharge means, an annular interstitial mass of illtering material filling said annular container chamber around and in communication with said air intake means thereof, said container having oil and dust mixture discharge means walls and opposed to said first mentioned convex wall section, whereby to provide a Venturi-like passage between said ingoing air passage and the interior of said oh basin section spaced above the surface level of the oil within the latter, said container convex wall section having oil and dust mixture discharge means communicating with said Venturi-llke passage, and means to collect and direct clean air emitted through the container air discharge means for delivery to a place of use.

4. An air filter apparatus as defined in claim 3, wherein the filtering material is arranged and graded to progressively decrease gradually from ported within said casing adjacently above the oil basin section, said container having its side walls inwardly spaced from the casing side walls to provide an annular ingoing air passage comsaid oil basin section, said confrom its central air intake means toward the container side walls and beneath said air discharge means, an annular interstitial tom and side mass of filtering material filling said annular container chamber, an inwardly directed convex wall section at the jun ture of the casing and oil basin section side walls, an outwardly directed convex wall section at the juncture of the container botwalls and opposed to said first mentioned convex wall section, whereby to provide a Venturi-like passage between said ingoing air passage and the interior of said oil basin section spaced above the surface level of the 011 within the latter, said container convex wall section having oil and dust mixture discharge means communicating with said Venturi-like passage, and means to collect and direct clean air emitted through the container air discharge means for delivery to a place of use.

6. An air filter apparatus as defined in claim 5, wherein the filtering material is arranged and graded to progressively decrease gradually from a maximum density adjacent the container air intake means to a minimum densit adjacent the container side walls and beneath the container air discharge means.

ALFRED M. GOODLOE. 

